That’s not really part of their mission. SS is traditionally a completely non-partisan role. They are not lackeys, just protectors.

Trump may (and will) bitch about it, but he’ll either abide by the terms of his probation or go to jail. If that means supervised drug tests, then that’s what he’ll have to do.

Offenders don’t really get a whole of say in the matter once it gets past the court system.